Antarctic Salp Genomics Cruise 2011

Monday, December 5, 2011

On Nov. 30th, we left Palmer Station and headed for King George Island and the NOAA field camp, dubbed Copabanga, where we were able to go ashore and see dense penguin colonies (with all three species - Gentoos, Adelies, and Chinstraps - apparently co-existing), while we hauled trash and propane tanks from the field camp. With good weather holding, the LMG got underway for Punta Arenas about 12:00 Noon.

For a short while, we thought the Drake Passage would lie down for our transit. But by the afternoon of Nov 30th, it was clear that we were in for a usual Drake crossing. Winds gusted over 50 kts and we pitched and rolled our way into the wind and through 5 m swells (Fig. 1). By morning, we reached the Straits of Maire (Isla de Estados), where we were more protected from the winds and waves, and conditions improved.

We pulled up to the dock in Punta Areanas about 10:00 AM on Dec. 1st. After the ship was cleared through Chilean customs, we were free to disembark. The science teams were allowed to stay onboard the LMG for the night, but some of us had reservations for nearby hotels (Fig. 2). In any case, everyone headed into Punta Arenas for some land-based R&R.

Figure 2 (left to right): The ship pulls up to the dock in Punta Arenas; our welcome party includes port agents and customs officials; soon the science teams are free to disembark and enjoy a sunny Spring afternoon in town. Photos Ann Bucklin

A post-cruise dinner the LMG11-10 was held that evening at Las Marmitas Restaurant (Fig. 3). Our celebratory dinner - which was also our Captain's birthday - concluded the cruise activities, which were judged overall to be both successful and enjoyable. The next day or soon thereafter, most of the scientists headed for home.

Figure 3. Everyone turned out for the LMG11-10 post-cruise dinner, which was also a birthday party for Captain Joe Abshire. Photos Peter H. Wiebe

So our Southern Ocean adventure is finished! We will keep our memories and mental images of Antarctica with us forever. We all feel that we have witnessed some of the most stunningly beautiful and unique landscapes and ocean vistas that our Earth can offer. But we are also longingly wishing for the comfort and welcome of home!

Tuesday, November 29, 2011

We returned for our second visit to Palmer Station, arriving as planned on the morning of Nov. 26th. The port call was needed to complete the cargo operations prevented by bad weather on our last visit and also to pick up scientists and Raytheon folks who returning from Palmer to Punta Arenas with us. Most of us also used the day for a quick trek up the Palmer glacier (Fig. 1).

During the afternoon, the Palmer Station residents generously arranged Zodiac trips – complete with safety briefings, emergency rations, and tour guides – to a nearby Adelie penguin rookery. We all suited up and headed off for a close-up view of Antarctic wildlife (Fig. 2).

Figure 2. A) Adelie penguin rookery near Palmer Station; a charter
sailboat is in the background. B) Paola and penguins. C) Climbing over
the rocks on the island are (from left) Ann, Joe, and Paola. Photos
Peter Wiebe.

Our visit to the island gave us a great look at Adelie penguins up
close. They have fascinating – and cute – behaviors that make simply
watching them great fun. The penguins coexist happily with elephant
seals, but the skua tries to drive the birds off their nests to steal
their eggs (Fig. 3).

The next day, with our passengers and cargo aboard, we dropped the lines for departure. Once away from the dock, the Palmer Station residents bade farewell to their departing residents with a traditional display of affection and respect (Fig. 4). Brrrrrrrr!

Figure 4. Palmer Station residents turn out to see the LM GOULD off
to Punta Arenas. A) Lines are dropped as we depart. B) Station folks
gather at the dock. C and D) The traditional send-off for departing
Palmer Station residents – a sign of affection and respect. Photos Peter
Wiebe.

As we steamed away from Palmer Station, we were again treated to close-up views of stunning Antarctic scenery. The good weather gave us another chance to for up-close views of wildlife, including groups of crabeater seals hauled out on the ice (Fig. 5).

Figure 5. A) View of Palmer Station as the LM GOULD departs. B)
Gathering on the 02 deck to view the sites, including crabeater seals
hauled out on the ice. C) Paola (left) and Ann on deck for departure.
Photos Peter Wiebe.

A bit later, we all headed out on deck again for a final view for this cruise of Neumayer Channel (Fig. 6). These mountains now look familiar to many of us. We will miss this vista!

Figure 6. Panoramic view of Neumayer Channel seen from the LM GOULD as
we steam away and North toward Punta Arenas. Photo and photomerge by
Peter Wiebe.

Sunday, November 27, 2011

Our last stop on our Salp Survey cruise was to Flanders Bay, a protected fjord off Gerlache Strait. We couldn’t have been luckier with the weather! The morning of Nov. 25th was sunny and calm, offering a stunning landscape of snow-covered peaks and glaciers and their reflected images in the still waters (Fig. 1).

Figure 1. View with reflections in the calm waters of Flanders Bay, Western Antarctic Peninsula region.

The good weather was particularly welcome since we had planned two launch two small boats from the LM Gould: one for salp and krill collection and the other for a small-scale bioacoustic survey. Both Zodiacs followed the ship’s trail through the ice (Fig. 2) to get closer to an area that Joe Warren had studied last year and dubbed “Krill City”. One zodiac was equipped for a small-scale bioacoustical survey of zooplankton distributions.

Figure 2. Left: The LM Gould clearing a path through the ice in Flanders
Bay for the small boat operations. Right: Joe Warren standing in a
zodiac equipped for small-scale bioacoustical surveys of zooplankton
distribution and abundance.

The second zodiac was launched with a team to collect salps and krill. Our scientific pursuits did not at all interfere with the fund and adventure of being on the water in a stunning landscape of snow and ice and sparkling clear water (Fig. 3).

Figure 3. Small boat operations in Flanders Bay. A) The acoustics
survey team included Kelley Watson (MT and Zodiac driver) and Katy
Wurtzell. B) The salp- and krill-collecting team included MST Melissa
Paddock (left) and MT Krista Tyburski (B) and Paola Batta-Lona (C). D)
Krista at the helm.

As we navigated around bergy-bits and ice-flows, we came across wildlife that seems unconcerned by such strange orange beings (the float coats are required for on-the-water work, so everyone is very similarly attired). We heard a minke whale come up for air and were surrounded by penguins who kept a watchful eye of us, but stood their ground (Fig 4).

Figure 4. Gentoo penguins were everywhere in the Bay. They hung out on
the ice and stood up to keep an eye on us.We also saw them porpoising
through the water, including one who followed our zodiac for several
minutes.

We also found at least some of what we were looking for. In Krill City, we collected the tiny larval (immature) krill that swarm under the ice bits (Fig. 5). These are the floating krill nurseries that contribute to the krill dense swarms of the Western Antarctic Peninsula region. The tiny krill feed on algae growing on the under-surface of the ice. We are particularly interested in the genetic make-up of these krill, which are a different generation from the juveniles and adults we have collected in other regions during our cruise.

Figure 5. Paola collecting larval krill from a floating “krill nursery” under a bit of ice.

The day in Flanders Bay was both thoroughly enjoyable and scientifically successful. For many of us, it was our favorite day of the cruise! It was also the last day of work for us. Later that night, we finished up our Salp Survey with a complete series of CTD cast, MOCNESS tow, and IKMT tow at the mouth of Flanders Bay. Then the technical team started breaking down our sampling gear and we steamed for our second port call at Palmer Station.

Thursday, November 24, 2011

Oceanographers are just like any other sort of people – they defy any categorization. Some of us are explorers, wishing to visit the farthest, deepest, remotest, or most challenging places on the Earth. Some of us are motivated by the technological challenges of understanding life in a medium into which we cannot see, requiring us to analyze or infer or extrapolate or interpolate or synthesize – or all of these – from bits of data to an integrated view. There are probably as many reasons folks do what they do as there are people who call themselves oceanographers!

One reason that I became a biological oceanographer is my (rather unscientific) appreciation for the animals that are the focus of my research. As a group, invertebrates (animals without backbones) range from absolutely lovely to really ugly to truly scary! I fell in love with marine invertebrates while I was a student at Oberlin College. I took a course in Marine Biology – a somewhat unlikely bet for “my favorite college course” in the fields of Ohio. The instructor was Dr. David Egloff, who somehow made the formalin-preserved, colorless, and looooong-dead animals we studied under our microscopes come alive. I came to appreciate the diversity of form driven by the many different ways that marine animals “solved” the challenges of life: feeding, swimming, floating, finding mates, reproducing, escaping predators, and so on.

Quite a few years later, I still feel pretty much the same way about marine invertebrates and especially about many zooplankton (animals that spend their entire lives drifting with ocean currents). I think most zooplankton are pretty cool and many are absolutely fascinating to watch while they are alive – one of the big benefits of going to sea. I wondered whether other members of our science teams on this cruise felt the same way. So I asked them: “Do you have a favorite zooplankton?” Here is what they said.

Paola Batta-Lona (Graduate Student in Marine Sciences, University of Connecticut)

Salps are my favorite zooplankton because they are transparent and simple-looking, but in fact – when you look at them closer or under the microscope – you realize they have interesting features. They share some characteristics with chordates like us. Salps also have an interesting and complex life cycle that involves sexual and asexual reproduction. This group of zooplankton is thought to play a major role in carbon export to the bottom of the ocean. There is some evidence indicating that salps are replacing key species like krill in the Southern Ocean. I find salps very interesting, and I look forward to find out more about them.

OK, here ya go, my favorite zooplankton is Clione limacina because how many times have you seen a flying snail underwater? They should have replaced the synchronized swimming hippos in Disney's Fantasia, because they are much more graceful, yet just as oddly shaped!

My favorite zooplankter is the copepod. I originally became interested in copepods because they are right whale food; but after studying them for several years, I began to appreciate them in their own right. I think the adaptation to over-winter by diapausing (which is basically like hibernation in bears) is fascinating and I'm also completely amazed by how quickly and how far they can move in short bursts for their body size.

Copepods are among the most abundant and diverse of zooplankton. These two copepods, a Euchaetidae (left) and Sapphirina metallina (right) show the diversity of form. Photos R.R. Hopcroft (Univ. Alaska)

My favorite zooplankton are larval octopi. I think they are beautiful and find the challenges in identifying them, which is based on the number and placement of chromatophores on the body, very interesting.

My favorite zooplankton is Diphyes antarctica. It's a siphonophore (need I say more?) These creatures are a colonial organism which means nobody really knows whether it's a single animal or a group of many animals working together in a coherent unit. The photo shows the bracht or nectophore (sometimes called the swimming bell) of the animal. Not shown are the tentacular appendages which it uses for feeding, as these are almost always destroyed by net sampling.

Fish eggs caught on this cruise with the little fish very much alive in the egg casings. Photo Melissa Patrician

My favorite zooplankton we have found this cruise would have to be the fish eggs. They don't look like much in the bucket, but when you take them inside and look under the microscope - they're beautiful. They have bright blue eyes and pretty geometric markings on their bodies. They are also moving inside the egg, opening and closing their gills. You can tell they are on their way to being a full grown fish!

Ann Bucklin (Professor of Marine Sciences, University of Connecticut)

Images of living zooplankton in a poster for the Census of Marine Zooplankton (CMarZ; see www.cmarz.org)

I have the unfair advantage of answering my own question last. So I will punt and reply that I reply that I like all marine zooplankton best! One reason is that I was one of the lead scientists for a global study of marine zooplankton diversity, called the Census of Marine Zooplankton (CMarZ). We made a poster with some of the images of living zooplankton from the CMarZ project (and some of them are shown above too). These are a small sampling of the 7,000 described species of 16 different phyla that live in the pelagic realm of the world oceans. I hope you will take a look at the photo galleries of living zooplankton on the CMarZ website (see http://www.cmarz.org).

-- Ann Bucklin (University of Connecticut)

P.S. I once asked my Oberlin College instructor, David Egloff, if I might do anything to express my gratitude to him for being a wonderful teacher and introducing me to marine invertebrates. He said, “Why don’t you give me a warm acknowledgment in one of your papers?” Just in case you are checking the blogosphere, Mr. Egloff, here’s another ‘warm acknowledgment!’

Wednesday, November 23, 2011

During our cruise, we sampled along Bransfield Strait as part of the survey for salps and krill. We entered the strait from the east by coming around Elephant and Clarence Islands after a series of stations along the Drake Passage north of the South Shetland Islands. The MOCNESS was towed obliquely to 1,000 meters at our Stns #14, #15, #17, #19, and #20 (Fig. 1).

Figure 1.Map of the stations in Bransfield Strait from which the
temperature and salinity data were mapped. The Strait lies between the
Western Antartic Peninsula and the South Shetland Islands. Stations are
indicated by number; islands are indicated by letter and named at right.

During each MOCNESS tow, data were collected on pressure (P), the temperature (T), and salinity (S). The data were used to create a longitudinal view of the physical oceanography of the Strait, called a hydrographic section, from the surface to 1,000 m. The pressure, temperature, and salinity values from both the down- and up-haul of the MOCNESS were assigned geospatial (latitude and longitude) coordinates. The values were then mapped in relation to Stn #14, which was at the northern end of our section (Fig. 2).

Figure 2. A) Temperature and B) salinity sections for Bransfield Strait.
Distance from Stn #14 is shown on the x-axis; tracks of the MOCNESS are shown as white vertical lines; the values were interpolated to provide the views shown using EasyKrig3.0 (Chu, 2004 and ftp://globec.whoi.edu/pub/software/kriging/easy_krig).

Although the number of profiles was small and the spacing wide, the T and S sections provide a basis for comparison with previous studies of the physical oceanography of Bransfield Strait.

Relatively warm deep (above O C) water from the offshore Antarctic Circumpolar Current enters the southern portion of the Bransfield Strait through a channel between Snow and Smith Islands. This water, which flows past Low Island and into the Strait between Deception and Trinity Islands, is identified by being warmer than 0o C and with a salinity of about 34.5 PSU. Such water is evident at Stn #20, which was situated between Low, Trinity, and Deception Islands.

According to Stern and Heywood (1994), “Deep basins within the Strait contain only Bottom Water, which is colder and more saline than the Antarctic Bottom Water of the Drake Passage and the Scotia Sea, and which is formed in situ during the seasonal freeze of Surface Water.” This water, known as the Bransfield Strait Basin Bottom Water, is also evident in our sections as the less than -1.0o C water in the center of the section at Stns #17 and #19 below about 400 m (see the dark blue area in Figure 2A). The cold (~ -0.5o C) less saline water at the surface is likely from Weddell Sea to the east of the Strait.

This type of analysis of the physical oceanography of the Southern Ocean regions we are sampling will be used to help us understand the ecology of the zooplankton we collect. In particular, the different origins of the water in the Bransfield Strait will have a strong influence on the distribution of the target species, salps and krill, that we are studying.